Poo Patrol: What Your Pet’s Poo Say About Their Health?

It’s not the most glamorous part of pet ownership, but every cat and dog owner knows that keeping an eye on your pet’s poo is part of caring for their health. Just like in humans, stool can reveal important clues about what’s going on inside. From diet changes to infections, dehydration, or more serious conditions, your pet’s digestive health signs often show up first in their litter tray or on your daily walk.

At Normanhurst Vet Practice, we encourage owners to take notice of what their pet’s stool looks like, feels like, and even smells like. While that might sound unpleasant, these observations are invaluable when it comes to early diagnosis and treatment.

Why Stool Matters in Pet Health

Your pet’s digestive system is a finely tuned machine. When everything is running smoothly, the result is a firm, brown, easy-to-pass stool. Changes in colour, consistency, or frequency may indicate:

Dietary issues (sudden food changes, intolerances, overeating)
Parasitic infections (worms, protozoa)
Bacterial or viral infections
Organ problems (liver, pancreas, intestines)
Stress or anxiety
Dehydration
Foreign body ingestion

Healthy digestion supports overall wellbeing. That’s why vets often ask, “What does your pet’s poo look like?” … it’s not small talk, it’s a diagnostic tool.

The Dog Poop Chart: What Healthy and Unhealthy Stools Mean

When it comes to dogs, colour and consistency are the two main indicators of stool health. Here are some of the most common types:

Chocolate brown, firm, log-shaped: Normal, healthy digestion.
Green: May indicate eating grass or a diet imbalance.
Black or tarry: Could point to internal bleeding higher in the digestive tract.
Red streaks: Blood from the lower intestines, rectum, or anal glands.
Yellow, greasy stool: Suggests fat malabsorption or liver/pancreatic disease.
Watery diarrhoea: Can signal infections, parasites, or a sudden diet change.
Hard, dry pellets: Constipation or dehydration.
Mucus-covered stool: Possible inflammation, colitis, or parasite load.

Dog Poop Chart: Stool Appearance, Health Indicators & What To Do

Appearance	What it means	What to do
Chocolate brown, firm log shape	Normal digestion	Nothing needed — this is ideal. Keep monitoring as part of your pet’s routine.
Green, or greenish-brown colour	Dietary upset or grass ingestion	Monitor for 24 hours. If green stool persists or your dog shows other symptoms (vomiting, lethargy), give us a call.
Black, tarry or very dark stool	Possible bleeding in upper GI tract	Give us a call immediately as this could be a medical emergency.
Brown stool with red streaks	Bleeding in lower intestines or rectum	Call us as soon as possible for advice, especially if bleeding is repeated or stool is soft/loose.
Yellow or greasy-looking stool	May indicate a liver, pancreas, or malabsorption issue	Make a vet appointment. These signs may indicate chronic conditions needing medical management.
Runny/Diarrhoea. Loose, watery consistency	Irritation, infection, parasites, or diet change	Provide fresh water to prevent dehydration. If diarrhoea lasts more than 24–48 hours, or if your dog is very young, elderly, or unwell, see a vet.
Small, hard, dry pellets	Constipation or dehydration	Ensure fresh water is available and encourage exercise. If constipation continues beyond two days or your dog strains repeatedly, contact your vet.

Disclaimer: These stool charts are intended as a general guide only. While all care has been taken in producing this information, stool changes can have many different causes. Always speak to our veterinary team at Normanhurst Vet Practice if you have any concerns about your pet’s digestive health, or if symptoms are persistent, severe, or accompanied by other signs of illness.

Stool Signs After Eating a Foreign Object

Dogs are notorious for swallowing things they shouldn’t — toys, socks, sticks, or bones can all cause blockages in the digestive tract. Stool changes can give clues that something is stuck.

Signs of possible impaction in dogs include:

Straining to pass stool but producing little or none
Small amounts of diarrhoea around a blockage (“overflow” diarrhoea)
Hard, dry, or unusually thin stools
Blood in the stool from irritation
Vomiting, drooling, loss of appetite, or abdominal pain

When to see a vet: If your dog is repeatedly straining, unable to pass stool, or showing signs of pain or vomiting, this is an emergency. Do not wait, blockages can become life-threatening.

The Cat Poop Chart: Litter Box Clues

Cats can be more subtle about their health, and many owners don’t regularly inspect the litter tray. However, stool changes in cats can be even more significant than in dogs.

Firm, brown, log-shaped: Healthy and normal.
Small, hard pellets: Constipation or dehydration, common in older cats.
Loose or watery diarrhoea: Parasites, infection, or dietary issues.
Yellow or greasy: Suggests liver or pancreas concerns.
Black/tarry: May indicate internal bleeding.
Blood in stool: Lower digestive tract issues, such as colitis.
Mucus: Possible inflammation or parasites.
Large, bulky stools: Could point to malabsorption conditions like IBD.

Cat Poop Chart: Stool Appearance, Health Indicators & What To Do

Appearance	What it means	What to do
Firm, brown, log-shape	Normal digestion	No action required. Continue monitoring litter tray as part of routine care.
Tiny, dry pellets	Constipation, dehydration	Encourage water intake and check diet. If constipation continues beyond 48 hours or your cat strains or cries in the litter tray, book a vet visit.
Loose/Watery Diarrhoea	Parasites, infection, diet issue	Seek vet advice if diarrhoea lasts more than 24 hours, is severe, or is accompanied by vomiting, lethargy, or loss of appetite.
Yellow, greasy-looking stool	Liver or pancreas disorder	Book a vet check promptly — this is often linked to more serious digestive or metabolic conditions.
Black or tarry stool	Possible internal bleeding (upper GI)	Contact your vet immediately. Black/tarry stools are considered urgent.
Brown stool with visible blood	Lower GI bleeding or colitis	If it happens once, monitor closely. If repeated, worsens, or your cat is unwell, arrange a vet appointment.
Slimy or coated with mucus	Inflammation, parasites	Monitor for recurrence. If mucus is persistent, or combined with blood or diarrhoea, see a vet.

Cats: Hair Ingestion and Impaction Risks

Cats naturally swallow hair during grooming. Normally, this passes through the stool or comes up as the occasional hairball. However, in some cases, hair can build up and cause digestive blockage (called a trichobezoar).

Signs of possible hair impaction in cats include:

Constipation or straining in the litter box
Small, hard stools with hair visible
Repeated retching or gagging without producing a hairball
Reduced appetite or vomiting
Lethargy or hiding behaviour

When to see a vet: If your cat hasn’t passed stool in more than 48 hours, is repeatedly vomiting, or seems lethargic and off food, seek veterinary attention promptly. Impactions may need medical or surgical intervention.

Prevention tips for cat owners:

Regular brushing, especially for long-haired cats
Specialised hairball-control diets or supplements — ask us at Normanhurst Vet about options like Hill’s Science Diet Hairball Control or Hill’s Science Diet Urinary Hairball Control
Encouraging hydration and exercise to keep digestion moving

For more advice, see Hill’s article on How to Help Your Cat Manage Its Hairball Problem.

Cat Diarrhoea: Vet Advice

One of the most common complaints we hear is, “My cat has diarrhoea, what should I do?” Occasional soft stool may not be serious, especially if your cat is otherwise bright and active. However, persistent diarrhoea in cats should never be ignored.

Causes include parasites, viral infections (like feline panleukopenia), sudden diet changes, stress, or underlying chronic illnesses. Because cats are prone to dehydration and can deteriorate quickly, we recommend booking a vet check if:

Diarrhoea lasts more than 24–48 hours.
There is blood or mucus in the stool.
Your cat becomes lethargic or stops eating.
Vomiting occurs alongside diarrhoea.

For more information on cat digestion and diarrhoea, see the RSPCA’s advice on cat health.

Healthy Dog Stool Colour: When to Worry

Dog owners are often surprised at just how much information stool colour provides. While chocolate-brown is the gold standard, variations may suggest medical concerns:

Orange/yellow: May indicate liver disease or bile duct issues.
Grey/white: Could point to pancreatic insufficiency.
Very dark black: Possible bleeding in the stomach or small intestine.
Bright red streaks: Local bleeding in the colon or rectum.

If changes are brief and your dog is otherwise happy, they may not require immediate action. But if stool colour changes persist beyond a day or two, or are accompanied by vomiting, appetite loss, or lethargy, consult your vet.

Other Digestive Health Signs to Watch For

Stool isn’t the only indicator of digestive problems. Other symptoms may include:

Excessive flatulence
Vomiting
Straining to defecate
Loss of appetite
Weight loss despite eating
Abdominal bloating

When these signs occur together with stool changes, they give your vet a clearer picture of what may be happening inside your pet’s digestive system.

Your Questions Answered

Why is my dog’s poop runny?
Runny poop is often caused by dietary changes, eating something inappropriate, parasites, or infection. Persistent diarrhoea needs a vet check.

What does mucus in dog stool mean?
Mucus is usually a sign of inflammation in the colon, sometimes linked to parasites or colitis.

What are cat constipation signs?
Cats may strain in the litter box, pass only small hard pellets, or cry out when defecating. Constipation can signal dehydration, poor diet, or underlying illness.

When should I see a vet about pet diarrhoea?
If diarrhoea lasts more than 48 hours, contains blood, or is accompanied by vomiting or lethargy, see a vet immediately.

Supporting Your Pet’s Digestive Health

Healthy digestion relies on a combination of good nutrition, hydration, and routine veterinary care. Tips include:

Feed a balanced diet: Ask your vet if a sensitive-stomach or prescription gastrointestinal food (such as Hill’s Science Diet Digestive Care) is right for your pet.
Avoid sudden food changes: Introduce new diets slowly.
Provide fresh water at all times to avoid dehydration.
Prevent parasites through regular worming treatments.
Encourage exercise to keep digestion regular.
Reduce stress: Changes in routine, loud noises, or new pets can upset sensitive tummies.

When to Book a Vet Appointment

While minor stool changes can happen from time to time, you should seek professional advice if you notice:

Sudden, unexplained diarrhoea or constipation.
Repeated vomiting alongside stool changes.
Black, tarry, or blood-streaked stools.
Changes that last more than two days.
Weight loss, lethargy, or loss of appetite.

At Normanhurst Vet Practice, we can run diagnostic tests (including faecal exams, blood work, and imaging) to pinpoint the cause. And if your pet hates the car ride? Our mobile VetVan can bring expert care to your door.

Final Word: A Healthy Gut = A Happier Pet

Your pet’s poo might not be the most glamorous subject, but it’s one of the most reliable indicators of health. By understanding pet digestive health signs, from colour and texture to frequency, you can spot early warning signs before they become major health problems.

Whether you’re decoding the dog poop chart, wondering what your pet’s stool means, or looking for cat diarrhoea vet advice, remember: when in doubt, always check with your local vet.

At Normanhurst Vet Practice, we’re here to help you keep your pets healthy, happy, and comfortable, inside and out.